The aims of the Pancreas Morphology core are threefold: 1) To provide centralized access to fixed, embedded, and sectioned pancreatic tissue, including timed harvest form mouse embryos; 2) to perform immunohistochemical /immunofluorescent staining and in situ hybridization services in support of the different projects; and 3) to perform isolation and in vitro organ culture of embryonic pancreatic tissue. A central tenet of this research program is that genes regulating pancreatic beta cell function must be considered in the context of an integrated tissue, leading to a heavy reliance on morphologic evaluation. It has also become clear that many genes required for normal beta cell function (e.g. Pdx1, Nkx6.1, Pax4, Pax6) also play critical role sin embryonic pancreatic development (1-3), requiring ready access to both adult and embryonic pancreatic tissue. By providing shared services for evaluation of tissues generated by the different projects, this core will serve as an important resource for the entire program. The provision of embryonic pancreatic tissue will enable each new mouse line to be characterized in terms of developmental phenotype. Application of a detailed battery of islet, acinar, and ductal lineage markers will provide a comprehensive analysis of phenotypes arising in different targeted mouse strains. In addition, the ability to propagate embryonic epithelial tissue in vitro will further extend studies regarding proliferation and differentiation in the different models.